Lightly grease a 23cm/9 inch baking tin (pan) and line with greaseproof paper.
Melt the milk chocolate and butter in a heatproof bowl set over a saucepan of simmering water.Leave to cool.
Sieve (strain) the flour into a separate mixing bowl and stir in the caster sugar.
Stir the eggs into the melted chocolate mixture,then pour this mixture into the flour and sugar mixture,beating well.Stir...,then pour the mixture into the tin (pan).
Bake in a preheated oven,180 oC/350 o/Gas Mark 4,for 30 - 35 minutes until firm to the touch.Leave to cool in the tin (pan) for 20 minutes,then turn out on to a wire rack.
